Concerning algebraic aspects considered in this paper, we follow the references [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}, [14]}, [15]} and also [16]}, [17]}, [18]}, [19]}, [20]}, [21]}.
